SIMULAÇÃO MATEMÁTICA E ANÁLISE EXPERIMENTAL DO DESEMPENHO DA DESIDRATAÇÃO DE LAMAS FECAIS EM LEITOS DE SECAGEM: Estudo de caso em Chimoio – Moçambique

The aim of the research was to simulate the optimum conditions for dewatering fecal sludge in drying beds, using a mathematical model based on the mass water balance. The exploratory study was carried out as a case study, with the construction and sizing of the Pilot Fecal Sludge Drying Infrastructure (IPSLF), consisting of a 30 m² area divided into four units: dewatering, wastewater treatment, filtration pit and vegetation area. Saturated hydraulic conductivity and initial porosity tests were carried out on eight drying beds, as well as daily analysis of parameters such as pH, temperature (T), electrical conductivity (EC), dissolved oxygen (DO), turbidity and total solids (TS), both in the field and in the laboratory. The experimental results showed minimal variations in porosity and saturated hydraulic conductivity between the beds, with averages between 0.006 m/s and 0.0002 m/s. The pH varied from 7.02 to 7.10, the EC from 2.12 mS/cm to 3.37 mS/cm, and the temperature between 19.5°C and 20.4°C. The final thickness of the sludge ranged from 7.37 cm to 8.11 cm, while the final humidity ranged from 72% to 78%. In the mathematical simulation, the final thickness values ranged from 12 cm to 21 cm, the humidity varied between 87.6% and 93.2%, and the mass of water drained between 20.14 kg and 24.20 kg. The results showed that the mathematical model fitted the experimental data well, making it a useful tool for the design and construction of drying beds for the treatment of fecal sludge.